1. Field of the Invention
The present invention relates to an image-reading apparatus.
2. Description of the Related Art
Examples of image-reading apparatuses include a manually-fed image-reading apparatus including an image-capturing unit and a conveying unit to convey a medium such as paper to the image-capturing unit, where a user feeds the medium to the conveying unit thereof, guiding the medium with the user's hands. Conventionally, for the sake of portability, such a manually-fed image-reading apparatus operates to read a medium using only an external power source such as a personal computer.
When a control unit of an electronic device hangs up or freezes, i.e., becomes stuck so as to be immovable and does not respond to any input, a user cannot turn the electronic device off even by operating an operation unit for turning the electronic device off. Consequently, the user needs to reset the control unit of the electronic device in another way (see Japanese Patent Application Laid-open No. 2003-92990). When a control unit controlling a conventional manually-fed image-reading apparatus hangs up or freezes, the manually-fed image-reading apparatus is reset by removing a power source cable connecting an external power source and the manually-fed image-reading apparatus and forcibly cutting the electricity supply from the external power source.
There are needs to read a medium to be read even under circumstances where no external power source is available. Mounting a secondary battery on a manually-fed image-reading apparatus is thought to be a solution for such needs. In the manually-fed image-reading apparatus on which the secondary battery is mounted, the secondary battery is charged by electricity supplied from the external power source, and under circumstances without electricity supply from the external power source, the manually-fed image-reading apparatus operates with electricity supplied from the secondary battery itself. When a control unit of the manually-fed image-reading apparatus hangs up or freezes, the control unit is reset by removing the secondary battery from the manually-fed image-reading apparatus and forcibly cutting the electricity supply from the external power source. However, when assuming a case where the secondary battery cannot be removed from the manually-fed image-reading apparatus, it is preferable that the control unit of the manually-fed image-reading apparatus be reset by an operation thereof made by the user. However, if the control unit is reset in a simple way, such a problem may occur that the control unit is reset during use of the manually-fed image-reading apparatus, which results in loss of data being read.